Electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (PHEVs) are becoming widespread. EV, HEV, and PHEV vehicles use power electronics systems to perform various functions, for example, battery chargers, inverters, DC/DC converters. The use of integrated power modules is typical in EV, HEV, and PHEV vehicles. These power modules perform power processing functions such as rectification, DC-DC conversion, DC-AC conversion, AC-DC conversion by means of high voltage silicon devices driven and controlled by system controllers, also referred to as control boards.
The control boards are usually located in the low-voltage network of the vehicle. The controllers implement the control loop of the entire power electronics system. Accordingly, the controllers need isolated measurements of critical signals from the high-voltage side of the power plant. For example, isolated measurements of input or output voltages and currents may be needed.
Existing current sensors for power electronics applications include closed-loop hall-effect sensors and magneto-resistive sensors. Hall-effect and magneto-resistive sensors provide isolation, and typically provide only the measurement signal. Shunt-based sensors also exist, and typically provide non-isolated measurement.
Further background information may be found in U.S. Pat. Nos. 4,677,536, 5,084,633, 5,274,350, 5,446,372, 5,457,591, 5,552,979, 5,610,532, 6,570,373, 7,309,980, 7,495,541. Further background information may be found in U.S. Pub. No. 2010/0023283.